Special features: • Provides more than 1500 outstanding color photographs that show the sequence of steps for all procedures involving self-ligating brackets from start to finish • Objectively evaluates the advantages and disadvantages of commercially available self-ligating bracket systems to help you make the best choices for your patients • Covers the full scope of treatment, including oral hygiene, adhesive techniques, biomechanics, esthetic choices, retention and stability, and more • Includes multiple case studies as well as information on risks, pitfalls, practical tips, and clinical pearls that aid in decision-making and reinforce the treatment concepts Written by a team of international specialists, this book is a quintessential guide for all practitioners who want to keep up to date with the latest developments in self-ligating brackets and offer state-of-the-art treatment techniques for their patients. This book is designed to be a useful introduction to newcomers to self-ligation as well as a guide for experienced orthodontists on how to successfully incorporate this highly popular technique into their practices. Bjoern Ludwig, MD, is Associate Professor at the University Clinic Homburg/Saar and in Private Practice in Traben-Trarbach, Germany. Dirk Bister, MD, DD, MOrth RCS Edinburgh, is Consultant Orthodontist, Guy’s and St. Thomas’ Dental Hospital, London, and Addenbrooke’s Hospital, Cambridge, UK. Sebastian Baumgaertel, DMD, MSD, FRCD(C), is Clinical Associate Professor, Department of Orthodontics, School of Dental Medicine, Case Western Reserve University, Cleveland, Ohio, USA. An award-winning international medical and scientific publisher, Thieme has demonstrated its commitment to the highest standard of quality in the state-of-the-art content and presentation of all of its products. Thieme’s trademark blue and silver covers have become synonymous with excellence in publishing.
ISBN 978-3-13-154701-9
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Self-Ligating Brackets
Promising numerous advantages in design, treatment efficacy, and reduced treatment time, self-ligating brackets have become a major part of modern orthodontic practice. Self-Ligating Brackets in Orthodontics: Current Concepts and Techniques summarizes contemporary information and clinical studies on these popular systems, integrating them with the authors’ practical and hands-on experience. Encompassing all aspects of treatment with self-ligating fixed appliances from biomechanics to material properties and also including diagnostic and therapeutic principles, this book provides a step-by-step visual guide to this groundbreaking field.
Ludwig / Bister Baumgaertel
A comprehensive overview of modern orthodontic treatment using self-ligating bracket systems—with evaluations of systems currently available
Self-Ligating Brackets in Orthodontics Current Concepts and Techniques
Bjoern Ludwig Dirk Bister Sebastian Baumgaertel
Oral Hygiene Heiko Goldbecher and Jens Bock
5 Basics
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Symptoms and Etiology of Caries Epidemiology of Caries
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Gingivitis and Periodontitis
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Hygiene Approaches for Fixed-Appliance Treatment Prophylactic Measures
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Active Measures 78 Oral Hygiene after Fixed-Appliance Treatment 81
Basics
b
a
Fig. 5.1a, b Plaque accumulation around self-ligating brackets.
brackets is increased. This becomes particularly visible in patients with poor oral hygiene and when a bracket has been opened.
This chapter focuses on the basic principles of periodontology and preventive dentistry as they relate to oral hygiene in patients wearing fixed appliances, with special emphasis on self-ligating brackets.
known that in patients with poor oral hygiene, caries may develop within weeks of fixed appliances being fitted.9 Although in ideal conditions, remineralization of initial lesions can be achieved, the damage is often irreversible.4,11,12 Remineralization is rarely seen and can only occur if the patient’s oral hygiene is of the highest possible standard. Regular general check-up visits with a dental hygienist or general dental practitioner are often the best way of achieving this. However, once the initial lesions have become established, and even if all the above favorable conditions are subsequently met, the patient may still progress from decalcification to carious lesions.
Due to the mechanical complexity and surface characteristics of self-ligating brackets, the risk of plaque accumulation around the
Basics Dental decay (caries), gingivitis, and periodontitis can be regarded as infectious diseases in the wider sense. A combination of numerous etiological factors plays a role in the pathology, but contrary to popular belief, genetic predisposition appears to be of minor importance. The level of oral hygiene appears to be the major cause of the above diseases. Fixed-appliance treatment is very likely to induce plaque, and it is therefore extremely important that the patient’s oral hygiene should be of the highest possible standard. It is therefore advisable for patients to use the services of a professional oral hygienist to achieve the best possible level of oral hygiene.
NOTE Plaque is primarily found in the retentive areas around the bracket base, and within a short period of time—sometimes less than a month—it may cause permanent decalcification, which ultimately leads to caries if left unattended.
It is widely known that after fixed appliances have been fitted, a bacteriological shift occurs in the oral cavity toward an increase in anaerobic, cariogenic bacteria. The same also applies to the use of self-ligating brackets, which often have larger undercuts and recesses than the traditional tie-wing brackets and therefore provide greater potential for plaque retention (Fig. 5.1). Demineralization around the bracket is a significant risk associated with fixed-appliance treatment in general. It is well
Symptoms and Etiology of Caries Caries is a disease of the dental hard tissues, with a high prevalence and incidence in adults. Carious disease is characterized by several phases, involving progression, stagnation, and remission. The more advanced stages of the disease are diagnosed clinically and may range from small initial lesions to open cavities. Active incipient caries is characterized by an “initial white spot” (Fig. 5.2a). This is often without loss of continuity in the dental surface. The surface of the affected area appears matt and is rough on probing. This is diagnostically different from the inactive initial carious lesion, which has the typical appearance of a smooth, shiny surface, often associated with a brown spot (Fig. 5.2b). Both active and inactive initial caries can progress further to create irreversible loss of tooth substance. The development and progression of carious lesions is characterized by a number of very diverse and variable factors. The combination of an increased number of pathogens, the presence of low-molecular-weight carbohydrates, and adequate residence time creates an environment in which tooth decay is likely to occur. In physiological conditions and good oral health, the oral cavity is colonized by a relatively stable flora, in terms of the quality and quantity of bacteria. However, this sensitive balance can easily be disturbed by various factors.
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Oral Hygiene Fig. 5.2a, b Carious lesions on the teeth
due to demineralization. Demineralization occurs to an acid environment. Initial carious lesions will appear when the balance between demineralization and remineralization tips toward the former.
a Typical decalcification due to plaque ac-
cumulation: this was due to poor oral hygiene around the brackets. Probing of the surface on the decalcified areas shows softened enamel.
b After widening of the interdental space with an elastic separator, a carious lesion becomes visible, which partly consists of a remineralized lesion (brown spot), while the majority consists of an active lesion (chalky white area). The pigmentation of brown spots takes place over several years as a result of the encapsulating coloring agents in the demineralized, porous enamel surface.
NOTE
Gingivitis and Periodontitis
Inappropriate oral hygiene and poor nutrition result in an increase in plaque, with a subsequent increase in pathogens.
Gingivitis and periodontitis are caused by bacterial colonization of the periodontal tissues. In etiological terms, the great majority of patients affected by periodontal disease also have increased plaque accumulation. The progression of the disease can be influenced by a number of factors and hormonal changes, medication, and symptoms of systemic diseases can all play a contributory role. Progression from chronic and long-standing to very aggressive disease may occur. A distinction is also made between localized disease (no more than 30% of the surfaces of the teeth affected) and generalized disease (more than 30% of the surfaces of the teeth affected).
The addition of glucose and saccharose (low-molecularweight carbohydrates) to the diet leads to an increase in the bacterial turnover of sugars into organic acids. This is associated with a decrease in the pH level in the oral cavity, which in turn induces demineralization of the dental hard tissues. The critical pH level below which demineralization occurs is between 5.2 and 5.7.8
Epidemiology of Caries
NOTE
The incidence and prevalence of caries are assessed using the decayed, missing, and filled teeth (DMFT) index. The results of a German study conducted in 2005 show that there was a significant reduction in DMFT during the 8-year study period. In comparison with the corresponding 1997 study, the DMFT declined from 1.7 to 0.7 teeth (58.8%) for 12-year-olds, and 70.1% of 12-year-olds and 46.1% of 15-year-old patients had a completely healthy dentition. The most important factors for reducing caries appear to be regular visits to the general dentist and provision of fissure sealants. Conversely, nearly 80% of all carious teeth were seen in 26.8% of the 15-year-olds. A significant reduction in caries in adults was observed for the first time (16.1% in 1997 versus 14.5% in 2005).10
Gingivitis is characterized by typical signs of infection—reddening, swelling, and bleeding on probing (Fig. 5.3). It is prevalent in all age groups and social classes.10
Progressive periodontal disease usually leads to further attachment loss, which is characterized by an increase in probing depth. To allow international comparisons, the use of the World Health Organization’s Community Periodontal Index (CPI) is recommended.
NOTE The risk of periodontal disease increases with the patient’s age.
Hygiene Approaches for Fixed-Appliance Treatment
a
b
Fig. 5.3a, b Gingivitis, accompanied by the typical symptoms. The lower labial segment is often particularly affected, as it is difficult to maintain good oral hygiene in the tight spaces between the brackets. Gingival hyperplasia becomes quickly established after
placement of fixed appliances and poor oral hygiene. The above images show the condition during orthodontic treatment (a) and following removal of the fixed appliances (b).
While gingivitis has a prevalence of 80% in children and adolescents, the prevalence of periodontitis in children is markedly lower than in adults. However, the epidemiological study mentioned above showed that 12.6% of all 15-year-olds have moderate periodontal disease and 0.8% have severe periodontal disease.10 In the 35–44-year-old age group, who are increasingly seeking orthodontic treatment, a large proportion of patients have periodontal disease. More than half of the patients enrolled in the epidemiological study mentioned had a CPI of 3 (medium severity) and 20.5% were suffering from a severe form of periodontal disease. In comparison with the 1997 study, there was an increase of 26.9% in the overall prevalence.10
particles and consequently offer good abrasion resistance against everyday wear and tear (such as brushing teeth). According to the manufacturer, the sealing of the surrounding surface area should last for at least 2 years and possibly even longer. Even after 2 years, there is still residual resin on the tooth surface in up to 70% of cases. Reports in the literature1,5 have shown that this system provides an equivalent bond strength to that of conventional adhesive systems and that remineralization of the dental enamel from the sealant’s reserve has a protective effect against caries.7,14 The operator should carefully remove the adhesive material in the vicinity of the bracket (Fig. 5.4) to allow oral hygiene. Particularly in the area near the gingivae, residual composite can rapidly lead to accumulation of food debris and consequent overgrowth of the gingivae.
Hygiene Approaches for Fixed-Appliance Treatment Prophylactic Measures Bonding Oral hygiene is more difficult after fixed appliances have been fitted. Efforts to maintain a patient’s oral health should therefore start at the bonding appointment. Removing excess composite around the brackets, which may contribute to plaque accumulation, is as important as sealing the tooth surface surrounding the brackets with fluoride varnishes or other protective agents. A new generation of sealants that gradually release fluoride are a promising development. Although they provide only a very thin covering of the tooth surface, these sealants allow complete polymerization, which is not inhibited by oxygenation. Two of the more widely used products are manufactured by Reliance Orthodontics (Maximum Cure and Pro Seal). The products are reinforced with filler
Fig. 5.4 Surplus
bonding material that was not removed immediately after bonding. The excess adhesive is discolored and has contributed to plaque accumulation. Good cleaning has been hindered by the surplus bonding material, particularly in the vicinity of the gingiva.
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Oral Hygiene CLINICAL PEARL Bonding agents that incorporate a light-sensitive dye are colored before setting and thus make it easier for the orthodontist to remove excess composite (Fig. 5.5).
Maintaining good oral hygiene is complex and time-consuming for patients receiving treatment with fixed appliances. In addition to the routine cleaning of all tooth surfaces incisal and gingival to the archwire, it is particularly important to pay attention to cleaning the interdental spaces. Patients therefore need to be instructed in depth on hygiene requirements with orthodontic fixed appliances on the day the appliances are placed. It is advisable to use aids such as V-shaped bristled toothbrushes, interdental brushes (such as TePe®), and single tufted brushes (Fig. 5.7). A number of studies have confirmed that for most patients, the time spent on brushing teeth is significantly less than the recommended time. It is therefore very important, particularly when considering treatment periods lasting several years, to monitor oral hygiene regularly and ideally support patients in their efforts to keep the teeth clean by encouraging regular visits to the hygienist, for example.
NOTE a
b
Fig. 5.5a, b After the bracket has been positioned on the tooth surface (a) the excess adhesive is clearly visible due to the added color and can be removed easily (b).
In addition to daily use of fluoride-containing toothpaste, we also recommend either a daily or weekly fluoride mouth rinse. Local fluoride applications can also be used, and fluoride-containing salt can be used as an adjunct to the above measures.
Active Tooth Movement After fixed appliances have been fitted, plaque undergoes qualitative and quantitative changes, and there is a noticeable increase in Streptococcus mutans. Bearing in mind the etiology and pathogenesis of carious and periodontal disease, the orthodontist should coordinate prophylactic measures specifically during orthodontic treatment with fixed appliances. Important measures include the following: • Instruction and motivation for the patient to practice good oral hygiene • Patient education on the etiology of caries and periodontal disease • Dietary counseling • Regular maintenance by dental hygienists, with professional cleanings and consultations • Topical fluoride applications • Use of fluoride-containing materials • Chemical plaque control In a review of the extensive literature, Chadwick et al.3 concluded that there is no single approach to oral hygiene that can be recommended. However, it is possible to significantly reduce the amount of decalcification by using fluoride-containing varnishes and/or sealants, fluoridecontaining gels, or fluoride-containing mouth rinses (Fig. 5.6).
Effective oral hygiene can also be achieved with an electric toothbrush. These can basically be divided into systems that have a rotating or oscillating head and sonic systems (Fig. 5.8). For systems with rotational or oscillating heads, patients can purchase special heads designed for fixedappliance treatment. Some studies have reported that sonic-based systems are superior in comparison with the rotational or oscillating
Fig. 5.6 Self-polymerizing fluoride varnishes to prevent demineralization and decalcification: Bifluorid 12 (Voco): NaF, CaF2; 55,900 ppm Duraphat (GABA): NaF; 22,600 ppm Fluor Protector (Ivoclar, Vivadent): Fluorsilan; 1000 ppm
Hygiene Approaches for Fixed-Appliance Treatment systems,9,13 but it remains to be seen whether these findings will be validated in subsequent studies. However, it is very important to remember that regular control visits and careful explanations are often the best way of keeping patients motivated and ensuring the best possible oral hygiene, regardless of which type of toothbrush is used. The peculiarities of the mixed and early permanent dentition in particular often require a very intensive oral hygiene regimen (Fig. 5.9). There is an increased incidence of caries during this period, as self-cleaning of the teeth is significantly reduced and good cleaning, particularly of the molars, can be difficult during their emergence. In addition, food retention and plaque accumulation may occur under residual opercular mucosa that partially covers the erupting teeth. Poor positioning of the teeth relative to the adjacent dentition can also give rise to carious lesions.
NOTE The fissures on the first and second molars are particularly susceptible to the development of carious lesions.
Apart from the genetically predetermined fissures of the first and second molars, their prolonged eruption time is an additional factor that promotes increased plaque accumulation. Newly erupted teeth are generally more susceptible to decay, as the posteruptive maturation of the enamel (with a reduction in the water content and an increase in crystal size) is only completed after several months or years after exposure to the oral cavity. Final resistance to acid-based demineralization is only established after the completion of this maturation process. In addition, malaligned teeth can increase the incidence of periodontal disease and caries, particularly in adults.6
Fig. 5.7a, b Various cleaning aids that may
be useful during orthodontic treatment. a Various toothbrushes: tufted brushes, interdental brushes. b A V-shaped toothbrush, with better access around fixed appliances.
b
a
a
b
c
Fig. 5.8a窶田 Electric toothbrushes. a Ultrasonic brush (Sonicare/Philips). b, c Several brush attachments for rotating and oscillating electric toothbrushes (Ortho Care Essentials/Oral B).
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Oral Hygiene
a
b
c
Fig. 5.9a–g a, b The high buccal position of the
d
e
f
g
canine has hindered good oral hygiene. c Fissure caries. As the enamel is highly susceptible to decay during the eruption phase of permanent teeth, patients need to be motivated to ensure particularly good hygiene during this stage of dental development. d–g Progression of fissure caries on 35 and 37. During the eruption of the second molar, initial caries has infiltrated the coronal aspect of the tooth. Full evaluation of the extent of the caries can often only be made radiologically (g).
Active Measures When a high incidence of caries has been noted, or a predilection to developing caries or simple gingivitis has been diagnosed, appropriate measures must be considered to prevent exacerbation or development of more serious oral pathology. Chlorhexidine can be administered in the form of a rinse, gel, or varnish. At doses higher than 100 ppm, chlorhexidine reduces the number of bacteria. Even low concentrations of 1 ppm or less have a bacteriostatic effect. Chlorhexidine can be administered at high dosages before the start of orthodontic treatment using a vacuum-formed tray (Fig. 5.10). For this to be successful, all plaque—soft and hard—has to be previously removed, and this should ideally be part of the orthodontic oral hygiene regimen. Ideally, patients should receive chairside demonstrations on how to use the soft splints. They are applied after the teeth have been appropriately cleaned, and 2–3 cm of chlorhexidine gel is placed in the tray and distributed evenly. The splint should then be worn for approximately 10 minutes in the evening, after the evening meal and following thorough oral hygiene. This should be continued for at least 14 days, and the treatment outcome should be documented. Patients requiring more intensive treatment can also benefit from using highly concentrated chlorhexidine varnishes, which are applied to areas where oral hygiene is difficult, such as the interdental spaces and fissures, and around the gingival margin. A small reservoir is applied
Fig. 5.10 Clinical use of a vacuum-formed tray containing chlorhexidine gel. and should ideally be left for approximately 5–15 minutes. The residual gel is then removed with a rubber cup. Biodent (Nijmegen, Netherlands) offers a varnish that is embedded in sandarac resin and is available in two different forms, under the trade name “EC 40” in a 35% concentration or as “BioC” in a 20% concentration. It is designed for particularly gentle application around the gingival margin. High-quality intraoral photography and regular assessment using oral hygiene indices such as the Approximal Plaque Index (API) and Sulcus Bleeding Index (SBI) make it possible to document treatment progress and help objectify the treatment results. It is important to have policies in place if oral hygiene is insufficient (as indicated by objective standards such as the various oral hygiene indices), so that the patient is appropriately warned and informed that the fixed appliances may have to be removed before the completion of treatment if oral hygiene standards deteriorate.
Hygiene Approaches for Fixed-Appliance Treatment ERRORS AND RISKS
NOTE Good orthodontic records also include documentation of oral hygiene (such as plaque retention, bleeding on probing, and probing depth) as well as previous caries.
Oral hygiene can be improved by patient education and plaque indicators are often very helpful (Fig. 5.11). After documentation of the findings and instructions on good oral hygiene, a number of professional aids for cleaning deposits on the teeth can be considered, for example, an ultrasonic scaler (Fig. 5.12) for hardened plaques, polishing paste or intraoral sandblasters such as the Prophy-Jet (Table 5.1).
a
Fig. 5.12 Ultrasonic sca-
lers, as shown here (SMS) should only be used cautiously with self-ligating bracket systems. The bracket mechanism may be damaged during the scaling process, and inadvertent bracket loss is also possible.
b
Fig. 5.11a, b a Plaque indicators: MIRA-2-Tone (Hager and Werken) and Plak-
Check (GUM). Under ultraviolet illumination, Plak-Check reveals plaque with a yellow color.
b The MIRA-2-Tone indicators differentiate between nature and new plaque. Plaque more than 3 days old appears blue, while pink coloring indicates plaque that is less than 3 days old.
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Table 5.1 Standard procedures for chairside care during fixed-appliance treatment: a clinical example for enhanced plaque control
Hygiene Approaches for Fixed-Appliance Treatment
Oral Hygiene after Fixed-Appliance Treatment The retention phase is important for maintaining orthodontic results and adequate oral hygiene continues to be paramount, and depending on the retainers used, may still involve a number of adjuncts. Removable retainers such as Hawley retainers, vacuum-formed retainers, and positioners allow good cleaning, as they can be removed for brushing. However, patients need to be aware that great care has to be taken when fixed retainers are used. Fixed retention is often used when orthodontic treatment has included extensive tooth movement, in adult patients, and all patients with previous periodontal disease.2 The advantage of fixed retention is the more or less permanently secured position of the front teeth. However, this has the disadvantage that it can create undercuts in areas that are particularly prone to plaque and calculus accumulation and this may consequently put patients at risk for periodontal problems or tooth decay (Fig. 5.13). Appropriate patient information (ideally both written and verbal) and consent to this type of retention is usually
REFERENCES 1. Bishara SE, Oonsombat C, Soliman MM, Warren J. Effects of using a new protective sealant on the bond strength of orthodontic brackets. Angle Orthod 2005;75(2):243–246 2. Bock JJ, Bock J. Grundwissen Kieferorthopädie. Balingen: Spitta Verlag; 2005 3. Chadwick BL, Roy J, Knox J, Treasure ET. The effect of topical fluorides on decalcification in patients with fixed orthodontic appliances: a systematic review. Am J Orthod Dentofacial Orthop 2005;128(5):601–606, quiz 670 4. Derks A, Katsaros C, Frencken JE, van’t Hof MA, Kuijpers-Jagtman AM. Caries-inhibiting effect of preventive measures during orthodontic treatment with fixed appliances. A systematic review. Caries Res 2004;38(5):413–420 5. El Bokle D, Munir H. An in vitro study of the effect of Pro Seal varnish on the shear bond strength of orthodontic brackets. World J Orthod 2008;9(2):141–146 6. Hensel E. Langzeitwirkung von Dysgnathien auf den Gesundheitszustand von Zahnhartsubstanzen und Parodontium [postdoctoral dissertation]. Greifswald, Germany: University of Greifswald; 1985 7. Hu W, Featherstone JD. Prevention of enamel demineralization: an in-vitro study using light-cured filled sealant. Am J Orthod Dentofacial Orthop 2005;128(5):592–600, quiz 670
advisable. The patient should be instructed to use adjuncts such as interdental brushes (TePe®), Superfloss, and Waterpik water flossers to maintain good oral hygiene around fixed retainers.
Fig. 5.13 Fixed retainer. This retainer had been fitted several months previously. While oral hygiene appears adequate, there are still signs of gingival inflammation and hyperplasia. The teeth should be professionally cleaned, and the amount of composite around the gingival margin should be reduced to allow for better oral hygiene.
8. Klimek J, Hellwig E. Kariesätiologie und -diagnose. In: Heidemann D, ed. Kariologie und Füllungstherapie. Munich: UrbanSchwarzenberg; 1999:3–42 9. Kneist S, Zingler S, Lux C. Therapiebegleitende Maßnahmen zur Kontrolle des Karies- und Demineralisationsrisikos bei kieferorthopädischer Behandlung. ZWR 2008;117:218–226 10. Micheelis W, Schiffner U, eds. Vierte Deutsche Mundgesundheitsstudie (DMS IV). Neue Ergebnisse zu oralen Erkrankungsprävalenzen, Risikogruppen und zum zahnärztlichen Versorgungsgrad in Deutschland 2005. Cologne: Deutscher Zahnärzte Verlag; 2006 11. Øgaard B, Rølla G, Arends J. Orthodontic appliances and enamel demineralization. Part 1. Lesion development. Am J Orthod Dentofacial Orthop 1988;94(1):68–73 12. Øgaard B, Rølla G, Arends J, ten Cate JM. Orthodontic appliances and enamel demineralization. Part 2. Prevention and treatment of lesions. Am J Orthod Dentofacial Orthop 1988;94(2):123–128 13. Roulet JF, Fath S, Zimmer P. Lehrbuch der Prophylaxeassistentin. Munich: Urban und Fischer; 2006 14. Salar DV, García-Godoy F, Flaitz CM, Hicks MJ. Potential inhibition of demineralization in vitro by fluoride-releasing sealants. J Am Dent Assoc 2007;138(4):502–506
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